Derrick Campana kneels beside Angel Marie, a three-legged mini horse who wears a prosthetic leg made by Campana. This first thing you notice about Derrick Campana's workshop is the machinery. Between the ovens, sewing machines and vacuum tubes lining the walls, it's easy to think Campana is a home economics teacher -- until you catch sight of the dusty paw prints. Campana and and his team use the tools not for domestic projects, but to build prosthetic and orthotic devices for animals. Campana, one of the world's leading experts in animal orthotics, is on a mission to give disabled pets and farm animals options for more mobile lives.